Zero: is a natural number that is used to express that no object meets a certain condition or that a measured value has this quantity with respect to a unit of measure._____________Annotation: The above characterizations of concepts are neither definitions nor exhausting presentations of problems related to them. Instead, they are intended to give a short introduction to the contributions below. – Lexicon of Arguments.

1. D. Hilbert und W. Ackermann, Grundzüge der theoretischen Logik, Berlin (6. Aufl. Berlin/Göttingen/Heidelberg 1972, §§ 1,2)_____________Explanation of symbols: Roman numerals
indicate the source, arabic numerals indicate
the page number. The corresponding books
are indicated on the right hand side.
((s)…): Comment by the sender of the contribution.
The note [Author1]Vs[Author2] or [Author]Vs[term] is an addition from the Dictionary of Arguments. If a German edition is specified, the page numbers refer to this edition.